This invention relates to a mold and a pressing apparatus having the mold for conducting press molding of molding material.
A mold is generally composed of a plurality of mold parts and is mounted in a pressing apparatus for use. The pressing apparatus presses molding material positioned between the mold parts to produce molded products. One example of such mold is a roof tile mold for molding roof tiles. In a case of the roof tile mold, a preform (roof tile clay material that is cut into a quadrate shape approximately corresponding to a shape of the roof tile) is first placed onto a lower mold part and is then pressed by an upper mold part. The pressed preform is deformed in conformity with an internal shape of the mold, or a shape of a cavity defined between the upper and lower mold parts, to produce a raw roof tile with a desired shape.
Engaging surfaces are provided in upper and lower mold parts for engaging with other engaging surface of opposite mold part to prevent egress of the deformed clay from the cavity during the pressing operation. When such mold is used for a long period of time, the engaging surfaces are worn out due to friction between the engaging surfaces. Especially, in a case of the roof tile mold, when the clay adheres to the engaging surfaces, the wearing process of the engaging surfaces is accelerated, and the engaging surfaces could be damaged by the clay particles. Furthermore, due to water contained in the clay, the engaging surfaces may rust, promoting the wearing process of the engaging surfaces.
An apparatus that restricts such wearing is disclosed in unexamined Japanese utility model publication No. 5-5408. The apparatus is a tile molding apparatus, wherein lubricating oil is sprayed near the engaging surfaces of the upper and lower mold parts.
However, such spraying of the lubricating oil cannot provide the sufficient amount of the lubricating oil to the entire engaging surfaces and inconveniently supplies the lubricating oil to portions where the lubricating oil is not needed, resulting in waste of the lubricating oil. Furthermore, even if the lubricating oil is successfully supplied to the engaging surfaces, the lubricating oil will be excessively supplied to the engaging surfaces, wasting the lubricating oil. Also, it is waste of the lubricating oil to supply the lubricating oil at each pressing operation.
Therefore, it is a primary objective of the present invention to provide a mold and a pressing apparatus capable of restricting the wearing of engaging surfaces.
To fulfill the above objective, the present invention provides a mold comprising first and second mold parts, wherein the first and second mold parts respectively have an engaging surface for engaging with each other during a pressing operation of molding material and a pressing surface for pressing the molding material, the mold being characterized by a lubricant supplying element that is formed in the engaging surface(s) of at least one of the first and second mold parts for supplying lubricant to the engaging surface(s), a first communicating passage that is formed in at least one of the first and second mold parts and is communicated with the lubricant supplying element, an inlet opening that is formed in an outer surface(s) of the mold part(s) having the first communicating passage for supplying the lubricant to the lubricant supplying element through the first communicating passage, a second communicating passage that is formed in at least one of the first and second mold parts and is communicated with the lubricant supplying element, and an outlet opening that is formed in an outer surface(s) of the mold part(s) having the second communicating passage for discharging the lubricant from the mold through the second communicating passage.
Furthermore, the present invention provides a mold comprising first and second mold parts, wherein the first and second mold parts respectively have an engaging surface for engaging with each other during a pressing operation of molding material and a pressing surface for pressing the molding material, the mold being characterized by a lubricant supplying channel that is formed in the engaging surface of the first or second mold part for supplying lubricant to the engaging surface, a first communicating passage that is formed in the first or second mold part and is communicated with the channel, an inlet opening that is formed in an outer surface of the mold part having the first communicating passage for supplying the lubricant to the channel through the first communicating passage, a second communicating passage that is formed in the first or second mold part and is communicated with the channel, and an outlet opening that is formed in an outer surface of the mold part having the second communicating passage for discharging the lubricant from the mold through the second communicating passage.
Also, to fulfill the above objective, the present invention provides a pressing apparatus including a mold comprising first and second mold parts, wherein the first and second mold parts respectively have an engaging surface for engaging with each other during a pressing operation of molding material and a pressing surface for pressing the molding material, a pressing means for holding the first and second mold parts of the mold and pressing the molding material that is disposed between the first and second mold parts by moving the first and second mold parts toward each other, and a counting means for counting the number of the pressing operations, the pressing apparatus being characterized by a lubricant supplying element that is formed in the engaging surface(s) of at least one of the first and second mold parts for supplying lubricant to the engaging surface(s), a first communicating passage that is formed in at least one of the first and second mold parts and is communicated with the lubricant supplying element, an inlet opening that is formed in an outer surface(s) of the mold part(s) having the first communicating passage for supplying the lubricant to the lubricant supplying element through the first communicating passage, a supplying device for supplying the lubricant to the inlet opening, and a control means for operating the supplying device based on a predetermined count of the counting means and a predetermined timing.
Furthermore, the present invention provides a pressing apparatus including a mold comprising first and second mold parts, wherein the first and second mold parts respectively have an engaging surface for engaging with each other during a pressing operation of molding material and a pressing surface for pressing the molding material, a pressing means for holding the first and second mold parts of the mold and pressing the molding material that is disposed between the first and second mold parts by moving the first and second mold parts toward each other, and a counting means for counting the number of the pressing operations, the pressing apparatus being characterized by a lubricant supplying channel that is formed in the engaging surface of the first or second mold part for supplying lubricant to the engaging surface, a first communicating passage that is formed in the first or second mold part and is communicated with the channel, an inlet opening that is formed in an outer surface of the mold part having the first communicating passage for supplying the lubricant to the channel through the first communicating passage, a second communicating passage that is formed in the first or second mold part and is communicated with the channel, an outlet opening that is formed in an outer surface of the mold part having the second communicating passage for discharging the lubricant from the mold through the second communicating passage, a supplying device for supplying the lubricant to the inlet opening, and a control means for operating the supplying device based on a predetermined count of the counting means and a predetermined timing.